I need a code to get the current value of the waveform from an audio file at specific frame
I would recommend looking at other forums on python for how to read audio files. This is not possible with blender’s normal API usage. You would need to go through Python.

Pygame. I believe that pygame.mixer can return a sound as an array which will give you the individual samples. This is what you need.
Wave. A module for reading the data in wave audio files.

You may not be able to install these Python packages to blender’s copy of Python, But you might be able to run python externally to convert an audio file into your own, native-Python-readable format for blender to open.